What is the name of this part?

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
You must be registered for see images attach
What’s this called? Part of the smog equipment, sits on the front of the engine attached to the alternator bracket.

You must be registered for see images attach
 
Last edited:

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
2,837
Reaction score
6,352
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
That is your decel (deceleration) valve. Should keep the engine from popping when letting off the throttle.
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
That is your decel (deceleration) valve. Should keep the engine from popping when letting off the throttle.
Thank you ! I’ll order a new one
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
That is your decel (deceleration) valve. Should keep the engine from popping when letting off the throttle.
I’ve checked all the usual supplier sites for this Deceleration valve, no luck ! Any suggestions?
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,889
Reaction score
4,024
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Does it have any type of part number on it? I know I was able to find one for my truck once I found the GM or ACDelco number. Sorry mine is a different style. Mine had a part number on the bracket and the pod in the lower left. It let me do a search to find aftermarket replacement parts.

You must be registered for see images attach
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
Does it have any type of part number on it? I know I was able to find one for my truck once I found the GM or ACDelco number. Sorry mine is a different style. Mine had a part number on the bracket and the pod in the lower left. It let me do a search to find aftermarket replacement parts.

You must be registered for see images attach
Thanks Craig, no part # anywhere. It appears to be the original factory part. My local NAPA parts store should be able to track it down
 

RecklessWOT

Full Access Member
Joined
Feb 20, 2015
Posts
2,548
Reaction score
4,744
Location
New Hampshire
First Name
Kevin
Truck Year
1987
Truck Model
V10 Suburban Silverado
Engine Size
350 TBI
Sometimes they're referred to as a throttle return dashpot, or just a carb dashpot. Even some older fuel injected vehicles have them. Though technically dashpots should be mechanical devices rather than vacuum. Still, you may have luck if you search that term
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
Sometimes they're referred to as a throttle return dashpot, or just a carb dashpot. Even some older fuel injected vehicles have them. Though technically dashpots should be mechanical devices rather than vacuum. Still, you may have luck if you search that term
Thanks
 

Turbo4whl

Supporting Member
Supporting Member
Joined
Oct 30, 2019
Posts
2,837
Reaction score
6,352
Location
Downingtown, PA
First Name
Wayne
Truck Year
1974
Truck Model
Jimmy
Engine Size
350
Sometimes they're referred to as a throttle return dashpot, or just a carb dashpot. Even some older fuel injected vehicles have them. Though technically dashpots should be mechanical devices rather than vacuum. Still, you may have luck if you search that term

The picture that @Craig 85 posted is a dash pot and it works differently to fix the same problem, engine popping on rapid throttle release.

Here is the basic issue, when you let off the throttle fast from a higher RPM the vacuum in the intake spikes very high. No air past the throttle plates, but the engine (as we know a big air pump) pulling hard. So what happens, the fuel that has puddled in the intake floats up and fires off causing the popping.

The dash pot method, holds the throttle so it will close slower, so no popping. The issue could be this dash pod will stick and cause wide open throttle.

Better (or maybe only safer) is the decel valve that lets some filtered air enter the intake so the vacuum doesn't spike high.

Many of the carburetor issues go away with fuel injection, but I still like carbs, I'm old school.
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
Good info, thanks. I accidentally broke off one of the fittings on this part, it’s the only reason I’m replacing it, everything was running fine before I broke it and
Because of its age it snapped off easily. Now I just need to locate one
 

SquareRoot

Full Access Member
Joined
Mar 18, 2017
Posts
3,656
Reaction score
6,593
Location
Arizona
First Name
Mike
Truck Year
85
Truck Model
K20
Engine Size
350
Edelbrock Pro-Flo. I promise you won't regret it. Buy once, cry once.
 

Craig 85

Full Access Member
Joined
Jan 25, 2017
Posts
3,889
Reaction score
4,024
Location
Nashville, TN
First Name
Craig
Truck Year
1985
Truck Model
K30 SRW
Engine Size
454/TH-400/NP205
Looks like this could be an ACDelco replacement number 214-438. The GM number supercedes this part. Found one on Amazon, but I can't read the full description in the drop down menu. It has two 305's, but says it one fits one of them. Hopefully they actually have it in stock. About $27 with free shipping. From what I can tell, there are no other manufacturers for this part.

https://www.wholesalegmpartsonline....ntrol-System-AIR-Valves/2681979/14034026.html

https://www.amazon.com/ACDelco-214-438-Deceleration-Valve-Diaphragm/dp/B000C9K1YO/ref=au_as_r?_encoding=UTF8&Make=Chevrolet|47&Model=G10|446&Year=1984|1984&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive
 

FireTruck1984

Full Access Member
Joined
Jan 7, 2019
Posts
2,816
Reaction score
9,028
Location
Michigan
First Name
Ted
Truck Year
1984 and 1984
Truck Model
High Sierra K1500 350. Sierra Classic C1500 305.
Engine Size
350, 305
Looks like this could be an ACDelco replacement number 214-438. The GM number supercedes this part. Found one on Amazon, but I can't read the full description in the drop down menu. It has two 305's, but says it one fits one of them. Hopefully they actually have it in stock. About $27 with free shipping. From what I can tell, there are no other manufacturers for this part.

https://www.wholesalegmpartsonline....ntrol-System-AIR-Valves/2681979/14034026.html

https://www.amazon.com/ACDelco-214-438-Deceleration-Valve-Diaphragm/dp/B000C9K1YO/ref=au_as_r?_encoding=UTF8&Make=Chevrolet|47&Model=G10|446&Year=1984|1984&ie=UTF8&n=15684181&newVehicle=1&s=automotive&vehicleId=2&vehicleType=automotive
Thank you sir, you’re a gentleman and a true patriot
 

Forum statistics

Threads
41,850
Posts
903,456
Members
33,362
Latest member
Dhatch84
Top